Avalanche Forecast
Issued: Jan 29th, 2020 5:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Storm Slabs.
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Avalanche Canada
Avoiding wind-exposed areas will be a good strategy to reduce avalanche risk and find the best riding. Monitor new snow depth and how the wind is building pillows on more sheltered features; those are the places to avoid.
Summary
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.
Weather Forecast
Wednesday Overnight: Wednesday was a very windy and reasonably snowy day; overnight the snow should end and the wind ease to only STRONG from the west with temperatures cooling to around -5 to -10 C.
Thursday: Another pulse of weather with 5 to 15 cm of snow, continued strong southwest winds, and gradually warming temps around -5 C near treeline.
Friday: Continued snow with today's amounts around 20 to 30 cm, continued moderate to strong southwest winds, and warmer. Freezing level rising to 1500 m to 2000 m.
Saturday: Cold front moves through with 5 cm (maybe up to 10 cm) of snow, moderate west winds with strong gusts, and quickly cooling temperatures back to around -10 C with freezing level returning to valley bottoms.
Avalanche Summary
WIndslabs were reported throughout the region, with this MIN report (with great photo) being a good example of the type of problem we're dealing with.
Looking forward, our wind slab problem isn't getting much chance to stabilize. Continued new snow and elevated winds continue to build new pillows on lee slopes and fresh snow that hasn't had time to stabilize on steeper wind-protected slopes.
Snowpack Summary
The upper snowpack reflects the seemingly never-ending pattern of snow & wind; there are widespread storm and wind slabs out there. But there's also lots of places with right-side-up powder that gradually blends into increasingly harder and stronger snow with distance from the surface.
In the mid-pack there's a layer of weaker surface hoar buried in late December remains a concern but is gaining strength. This layer is found across much of the North Rockies region but our focus is around McBride and the McGregors/Torpy. It's a classic surface hoar layer that most prominent in sheltered treeline features 50 to 150 cm below the surface.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Watch for rapidly changing conditions during periods of heavy loading from new snow, wind, or rain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Problems
Wind Slabs
Wind slabs of varying age and reactivity can still be found in the alpine and upper treeline, with northeast to northwest aspects likely to hold the most recent slabs as a result of mainly south winds. This problem won't get much of a chance to stabilize before another pulse of new snow and wind creates new slabs to manage on Wednesday.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
With continued snowfall accumulations treeline elevations could see a storm slab avalanche problem develop on steeper slopes in open, wind protected glades.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Valid until: Jan 31st, 2020 5:00PM
